The $20^{th}$ term of an $A.P.$ is $40$ and the common difference is $2$. Then,its second term is $\ldots \ldots \ldots \ldots$

The $4^{\text{th}}$ term from the end of the $AP: -11, -8, -5, \dots, 49$ is

Determine whether the following sequence is an $A.P.$ or not. (Assume that the pattern continues.) If it is an $A.P.$,find its $n^{th}$ term: $1, 4, 9, 16, \ldots $

Which of the following sequences is an $A.P.$?

For the $A.P.$ $\frac{3}{2}, \frac{7}{2}, \frac{11}{2}, \frac{15}{2}, \ldots,$ the common difference is

The $A.P.$ with $a = -3$ and $d = -2$ is..........